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        <p>Library Version 11.2.5.3</p>
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          <th colspan="3" align="center">DB_ENV-&gt;backup()</th>
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          <td width="20%" align="left"><a accesskey="p" href="envadd_data_dir.html">Prev</a> </td>
          <th width="60%" align="center">Chapter 5. 
                The DB_ENV Handle
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    <div class="sect1" lang="en" xml:lang="en">
      <div class="titlepage">
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          <div>
            <h2 class="title" style="clear: both"><a id="envbackup"></a>DB_ENV-&gt;backup()</h2>
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      <pre class="programlisting">#include &lt;db.h&gt;

int
DB_ENV-&gt;backup(DB_ENV *dbenv, const char *target, u_int32_t flags); </pre>
      <p>
        The <code class="methodname">DB_ENV-&gt;backup()</code> method performs a hot
        backup of the open environment. All files used by the environment
        are backed up, so long as the normal rules for file placement are
        followed. For information on how files are normally placed relative
        to the environment directory, see
        <a href="../../programmer_reference/env_naming.html" class="olink">Berkeley DB File Naming</a> in the <em class="citetitle">Berkeley DB Programmer's Reference Guide</em>.
    </p>
      <p>
        By default, data directories and the log directory specified
        relative to the home directory will be recreated relative to the
        target directory. If absolute path names are used, then specify
        <code class="literal">DB_BACKUP_SINGLE_DIR</code> to the <code class="literal">flags</code>
        parameter. 
    </p>
      <p>
        This method provides the same functionality as the
        <a class="xref" href="db_hotbackup.html" title="db_hotbackup">db_hotbackup</a>
        utility. However, this method does not perform the housekeeping
        actions performed by the <code class="literal">db_hotbackup</code> utility.
        In particular, you may want to run a checkpoint before calling this
        method. To run a checkpoint, use the 
        <a class="xref" href="txncheckpoint.html" title="DB_ENV-&gt;txn_checkpoint()">DB_ENV-&gt;txn_checkpoint()</a>
        method. For more information on checkpoints, see
        <a href="../../programmer_reference/transapp_checkpoint.html" class="olink">Checkpoints</a> in the <em class="citetitle">Berkeley DB Programmer's Reference Guide</em>.
    </p>
      <p>
        To back up a single database file contained within the environment,
        use the
        <a class="xref" href="envdbbackup.html" title="DB_ENV-&gt;dbbackup()">DB_ENV-&gt;dbbackup()</a>
        method.
    </p>
      <p>
        This method's default behavior can be changed by setting backup
        callbacks. See 
        <a class="xref" href="envset_backup_callbacks.html" title="DB_ENV-&gt;set_backup_callbacks()">DB_ENV-&gt;set_backup_callbacks()</a> 
        for more information.  Additional tuning parameters can also be set
        using the
        <a class="xref" href="envset_backup_config.html" title="DB_ENV-&gt;set_backup_config()">DB_ENV-&gt;set_backup_config()</a> method.
    </p>
      <p>
         The <code class="methodname">DB_ENV-&gt;backup()</code> method may only be
         called after the environment handle has been opened.
    </p>
      <p>
         The <code class="methodname">DB_ENV-&gt;backup()</code> <span>
            <span>
                  method returns a non-zero error value on failure and 0 on success.
            </span>
            
        </span>
    </p>
      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idp51230112"></a>Parameters</h3>
            </div>
          </div>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp51243928"></a>target</h4>
              </div>
            </div>
          </div>
          <p>
                 Identifies the directory in which the back up will be
                 placed. Any subdirectories required to contain the backup
                 must be placed relative to this directory. Note that if
                 the backup callbacks are set, then the value specified to
                 this parameter is passed on to the <code class="literal">open_func()</code>
                 callback. If this parameter is NULL, then the target must
                 be specified to the <code class="literal">open_func()</code>
                 callback.
             </p>
          <p>
                 This directory, and any required subdirectories, will be
                 created for you if you specify the
                 <code class="literal">DB_CREATE</code> flag on the call to this
                 method. Otherwise, if the target does not exist, this
                 method exits with an <code class="literal">ENOENT</code>
                 error return.
             </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp51252240"></a>flags</h4>
              </div>
            </div>
          </div>
          <p>
                The <span class="bold"><strong>flags</strong></span> parameter must
                be set to 0 or by bitwise inclusively 
                <span class="bold"><strong>OR</strong></span>'ing together one or more of
                the values:
            </p>
          <div class="itemizedlist">
            <ul type="disc">
              <li>
                <p>
                        <code class="literal">DB_BACKUP_CLEAN</code>
                    </p>
                <p>
                        Before performing the backup, first remove all
                        files from the target backup directory tree.
                    </p>
              </li>
              <li>
                <p>
                        <code class="literal">DB_BACKUP_FILES</code>
                    </p>
                <p>
                        Back up all ordinary files that might exist in the
                        environment, and the environment's subdirectories.
                    </p>
              </li>
              <li>
                <p>
                        <code class="literal">DB_BACKUP_NO_LOGS</code>
                    </p>
                <p>
                        Back up only the <code class="literal">*.db</code>
                        files. Do not backup the log files.
                    </p>
              </li>
              <li>
                <p>
                        <code class="literal">DB_BACKUP_SINGLE_DIR</code>
                    </p>
                <p>
                        Regardless of the directory structure used by the
                        source environment, place all back up files in the
                        single directory identified by the
                        <code class="literal">target</code> parameter. Use this
                        option if absolute path names to your environment
                        directory and the files within that directory are
                        required by your application.
                    </p>
              </li>
              <li>
                <p>
                        <code class="literal">DB_BACKUP_UPDATE</code>
                    </p>
                <p>
                        Perform an incremental back up, instead of a full
                        back up. When this option is specified, only log
                        files are copied to the target directory.
                    </p>
              </li>
              <li>
                <p>
                        <code class="literal">DB_CREATE</code>
                    </p>
                <p>
                        If the target directory does not exist, create it
                        and any required subdirectories.
                    </p>
              </li>
              <li>
                <p>
                        <code class="literal">DB_EXCL</code>
                    </p>
                <p>
                        Return an <code class="literal">EEXIST</code> error if a
                        target backup file already exists.
                    </p>
              </li>
              <li>
                <p>
                        <code class="literal">DB_VERB_BACKUP</code>
                    </p>
                <p>
                        Run in verbose mode, listing operations as they are
                        completed.
                    </p>
              </li>
            </ul>
          </div>
        </div>
      </div>
      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idp51283200"></a>Errors</h3>
            </div>
          </div>
        </div>
        <p>
             The <code class="methodname">DB_ENV-&gt;backup()</code> <span>
            <span>
                 method may fail and return one of the following non-zero errors:
            </span>
            
        </span>
        </p>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp51268432"></a>EEXIST</h4>
              </div>
            </div>
          </div>
          <p>
                <code class="literal">DB_EXCL</code> was specified for the
                <code class="literal">flags</code> parameter, and an existing target
                file was discovered when attempting to back up a source
                file.
            </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp51269320"></a>ENOENT</h4>
              </div>
            </div>
          </div>
          <p>
                The target directory does not exist and <code class="literal">DB_CREATE</code>
                was not specified for the <code class="literal">flags</code>
                parameter.
            </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp51278968"></a>EINVAL</h4>
              </div>
            </div>
          </div>
          <p>
                An invalid flag value or parameter was specified.
            </p>
        </div>
      </div>
      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idp51273504"></a>Class</h3>
            </div>
          </div>
        </div>
        <p>
            <a class="link" href="env.html" title="Chapter 5.  The DB_ENV Handle">DB_ENV</a>  
        </p>
      </div>
      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idp51280048"></a>See Also</h3>
            </div>
          </div>
        </div>
        <p>
             <a class="xref" href="env.html#envlist" title="Database Environments and Related Methods">Database Environments and Related Methods</a> 
        </p>
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